Good Acceptance Criteria cannot stand alone. It has to be derived from the requirement description - e.g. User Story. Therefore, a good requirement description is the starting point.
However, without knowing the requirement details is hard to say if your example is a good one or not. But anyway, let's take a look at the basics.
Acceptance Criteria should include functional and non-functional criteria which has to be fulfilled by the final product to confirm that the related requirement is realized.
Now, let's take a look again at your example.
Given <source system> has pushed the <account details file> into the specified location
when <file system> receives this <account details file>
then <file system> should pre-process raw <account details file> and transform it into consumable data and must check the processed <account details file> against the <validation rules>
*<validation rules>*
1. Raw <account details file> data should match with the processed <account details file> data in <file system>
2. Record count should match between raw <account details file> and processed <account details file> for file header, footer and body.
First of all, you are using the Given-When-Then formula which is primarily used to define Acceptance Tests. So I don't think this is a good approach to define Acceptance Criteria at all.
Acceptance Tests should be derived from the Acceptance Criteria. Acceptance Criteria helps to make clear when a requirement is done while a acceptance test is used to verify if it's really done. Imho a good way to write Acceptance Criteria is to write them as a bullet list.
- File System has received pushed file ...
- File System has validated the received file by validation rules ...
- ...
Beside that your example doesn't include any non-functional criteria (Performance, Fault Management, Robustness, Comprehensibility, ...). As far as I can assess some non-functional criteria for your case might be.
The file system process, transforms and validates 1000 files within ...
If a account details file is not valid it has to be moved/deleted/marked ...
If the file system is not available pushed files should be processed when the file system is available again ...
The file system logs every received file ...
- ...
